The project is essentially a lightsaber. I've seen flashlights that put out high wattage LED current successfully so I have to think it's possible.

I was using a STCS2 from ST Microelectronics, and except for the heat it worked great.http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATASHEET/CD00185795.pdf

Anything similar that would run cooler? The problem is that the V difference between the VIN and the LED VFWD will vary a lot depending on LED choices and battery solutions used. One such issue is using several for RGB control.. VFWD is different for the R G and B dies.... so for instance red overheats when B and G are fine.

Or, is the entire approach faulty and I should be doing something else?

I'm trying to design something that will work with several LEDs, although it will start with a single driver under PWM control. The eventual goal is a "shield" designed to fit on an Arduino Nano. (LED Driver, microSD, Accelerometer, Audio Amp)

The idea being is you want just a single color LED the driver will be on the board. (If you wish to drive RGB(A) then you would add on a 2x or 3X driver sub-board.) Most folks would just want to drive one LED.... somewhere between 350 ma to 1200 ma.

Although I was running mine using the STCS2 @1200 ma. (I'm OK with a lightsaber LED that only burns for thousands of hours instead of 10's of thousands. ;-) 4xAA Nimh Pack so 4.8v source.http://www.ledengin.com/files/products/LZ4/LZ4-00MA00.pdf(Opps.. meant to include link to LED.)

Depending on your power requirements, you are likely looking for a to220-5 chip. The SimpleSwitcher from National would fit the bill - and it is multi-sourced, to boot. The ON equivalent of it is also a good choice.

Another way is to get those dc/dc converters from ebay and mod them - easily done.

Yes, that drives the LEDs, but part of the "illusion" is carried by ramping up the light so it appears to extend down the blade, adding a pulse or shimmer effect when the blade is extended, a flash coinciding with an impact and blade retraction effects (etc.) so the PWM control is part of the whole package.

My main goal is to make an open platform lightsaber controller available... there are commercial controllers out there up to $150 or so but not much for folks who would brew thier own. It will be larger than most "pro" ones but being programmable opens a lot of possibilities (hopefully some of which I haven't though of, LOL.)